Method and apparatus for preheating glass batch

Abstract

A process and apparatus for preheating glass batch ingredients is disclosed. The invention uses a heat exchange method that preferably employs furnace exhaust gases. The heated batch then is fed to a glass melting furnace.

We claim: 
     
       1. A process for producing glass by charging to a melting furnace and melting therein a particulate glass batch, including the steps of: heating durable heat transfer media, larger in particle size than the glass batch, by direct contact with exhaust gases from the melting furnace;   introducing the hot media into one end of an inclined container rotatable about an axis having the same inclination as the container;   introducing the particulate glass batch into the other end of the container with the batch charging end of the container elevated above the media charging end;   rotating the container, during rotation the batch and media tumbling and moving over each other in heat transfer relationship;   moving the glass batch in one direction through the rotating container towards the lower end for discharge and moving the hot media in the opposite direction for discharge at the elevated end; and   discharging hot batch at the lower end of the container through openings that allow the batch to pass freely through but that prevent the media from passing.   
     
     
       2. A process for producing glass by charging to a melting furnace and melting therein a particulate glass batch, including the steps of: heating durable heat transfer media, larger in particle size than the glass batch, by direct contact with exhaust gases from the melting furnace;   introducing the hot media into one end of an inclined container rotatable about an axis having the same inclination as the container;   introducing the articulate glass batch into the other end of the container with the batch charging end of the container elevated above the media charging end;   rotating the container, during rotation the batch and media tumbling and moving over each other in heat transfer relationship;   axially moving the glass batch in one direction through the rotating container towards the lower end for discharge and axially moving the hot media in the opposite direction for discharge at the elevated end; and   discharging hot batch at the lower end of the container through openings that allow the batch to pass freely through but that prevent the media from passing.   
     
     
       3. A process according to claims 1 or 2 wherein the media and batch each form gradients and generally flow downhill in a direction along its gradient. 
     
     
       4. A process according to claims 1 or 2, wherein the hot media has a spherical shape. 
     
     
       5. A process according to claims 1 or 2 wherein the media is removed from the container by moving along a spiral path through a scroll connected to and located within the container, and communicating with a media exit to the exterior of the container. 
     
     
       6. A process according to claim 1 or 2 wherein the media is removed from the container by moving along a spiral path from an outer, interior region of the container to a centrally arranged media exit communicating to the exterior of the container. 
     
     
       7. An apparatus for preheating particulate glass batch comprising: means for heating durable heat transfer media by direct contact with exhaust gases from a melting furnace;   a container rotatable about an axis, the axis being inclined to the horizontal;   means for introducing the hot media, larger in particle size than the glass batch, into the lower end of the container for movement towards the elevated end for discharge;   means for introducing particulate glass batch into the elevated end of the container for movement towards the lower end for discharge;   means for rotating the container along the inclined axis;   means associated with the interior of the container for tumbling and moving the particulate glass batch in direct contact with hot media during rotation of the container to heat the glass batch prior to charging to a melting furnace; and   means for discharging hot batch at the lower end of the container having openings of a size that allows the batch to pass freely through the openings but that prevents the media from passing through the openings.   
     
     
       8. An apparatus according to claim 7 wherein the means for removing hot batch from the container is a grate-like member forming the sidewall of the container adjacent one end wall of the container, the openings of the member having a size that allows the batch to pass freely through the openings but that prevents the media from passing through the openings. 
     
     
       9. An apparatus according to claim 7 where the means for removing hot batch from the container is a screen or perforated plate. 
     
     
       10. An apparatus according to claim 7 wherein the container is a cylindrical drum. 
     
     
       11. An apparatus according to claim 7 wherein an arrangement of protruberances are attached to the interior of the container. 
     
     
       12. An apparatus according to claim 7 wherein the means for charging the batch extends into the interior of the container. 
     
     
       13. An apparatus according to claim 7 wherein the means for removing cooled media from the container includes a scroll attached to the container and extending into the container. 
     
     
       14. An apparatus according to claim 13 wherein the scroll has openings of a size that allows batch to pass freely through the openings but that prevents the media from passing through the openings. 
     
     
       15. An apparatus according to claim 14 wherein the scroll is at least 70 percent openings. 
     
     
       16. An apparatus according to claim 13 wherein the scroll is formed of screen, perforated plate or expanded metal. 
     
     
       17. An apparatus for preheating particulate glass batch comprising: a rotatably mounted container;   an end wall defining an opening at each of the opposite ends of the container;   means for charging particulate glass batch to one of the openings in one end wall of the drum;   a vertical bed preheat hopper;   means for charging media to the hopper;   means for charging exhaust gases from a glass melting furnace to the hopper;   means for bringing the media in direct contact with the exhaust gases;   means for removing hot media from the hopper and charging the hot media to the opening in the other end wall of the container;   means for removing hot batch from the container; and   means for removing cooled media from the container;   wherein the means for charging batch and the means for removing cooled media are at or adjacent one end of the container and the means for removing hot batch and the means for supplying hot media are at or adjacent the other end of the container;   wherein the means for removing cooled media from the container includes a scroll attached to the container and extending into the container; and   wherein the scroll has openings of a size that allows batch to pass freely through the openings but that prevents the media from passing through the openings.   
     
     
       18. An apparatus according to claim 17 wherein the scroll is at least 70 percent openings. 
     
     
       19. An apparatus for preheating particulate glass batch comprising: a rotatably mounted container;   an end wall defining an opening at each of the opposite ends of the container;   means for charging particulate glass batch to one of the openings in one end wall of the container;   means for charging hot media to the opening in the other end wall of the container;   means for removing hot batch from the container; and   means for removing cooled media from the container;   wherein the means for charging batch and the means for removing cooled media are at or adjacent one end of the container and the means for removing hot batch and the means for charging hot media are at or near the other end of the container;   wherein the means for removing cooled media from the container includes a scroll attached to the container and extending into the container; and   wherein the scroll has openings of a size that allows batch to pass freely through the openings but that prevents the media from passing through the openings.